Explanation
Weight at a chosen adult BMI
There is no single ideal body weight determined by height alone. This calculator reverses the adult BMI formula for a BMI value you choose, without recommending a target or labelling it ideal.
Choose the question and enter values
Enter height in centimetres, an explicit BMI scenario and adult age. The result answers a mathematical question about that scenario; it does not decide whether you should change your weight.
w = B × (h ÷ 100)², with w in kilograms, B the chosen BMI and h the height in centimetres.
| h | Height |
|---|---|
| B | Chosen BMI |
| A | Age |
200 cm at a chosen BMI of 20
| Height | 200 |
|---|---|
| Chosen BMI | 20 |
| Age | 30 |
| Result | 80 kg |
Chosen BMI 20 × (200 ÷ 100)² = 80 kg. Adult age context: 30. This scenario does not determine an ideal personal weight.
160 cm at a chosen BMI of 25
| Height | 160 |
|---|---|
| Chosen BMI | 25 |
| Age | 40 |
| Result | 64 kg |
Chosen BMI 25 × (160 ÷ 100)² = 64 kg. Adult age context: 40. This scenario does not determine an ideal personal weight.
180 cm at a chosen BMI of 25
| Height | 180 |
|---|---|
| Chosen BMI | 25 |
| Age | 50 |
| Result | 81 kg |
Chosen BMI 25 × (180 ÷ 100)² = 81 kg. Adult age context: 50. This scenario does not determine an ideal personal weight.
Diagram of this result
Two aligned scales convert BMI to kilograms at the entered height; the marker is the chosen BMI. The scale is for orientation only and does not identify an ideal or healthy weight.
The exact numbers and their units are stated in the visible text. Predictions and scenario inputs are not medical measurements or prescriptions.
Common mistakes
Do not confuse a reference BMI with a personal health goal. Muscle, body composition, medical history and other circumstances matter beyond this arithmetic.
Assumptions and limits
Adult ages 20–120, height 100–250cm, chosen BMI 10–50. Bounds are scenario controls, not a recommended range. Not for children, pregnancy or a treatment plan. No weight-change advice is generated. Educational information only, not medical advice, diagnosis or an individualized nutrition plan.
Why does this not give one ideal weight?
An individual health goal cannot be derived from height alone. The chosen BMI is an explicit assumption, and the output only expresses it as kilograms.
Method and references
This is an algebraic rearrangement of CDC’s metric BMI formula: https://www.cdc.gov/growth-chart-training/hcp/using-bmi/calculating-bmi.html . CDC’s overview explains why BMI needs context: https://www.cdc.gov/bmi/about/index.html . Neither source endorses the calculator’s example BMI as an individual goal.